The present invention relates generally to pressurized or aerosol type containers having a flexible chamber and a freely movable object disposed in the container for mixing the product in the container. More particularly, the present invention relates to apparatus for maintaining free movement of the mixing object in such containers, and to containers including such apparatus.
In pressurized or aerosol containers of the type which include a flexible chamber and a freely movable object, e.g. a glass or steel ball, in the container for mixing the product upon shaking the container, it is possible for the movable object to be rendered immobile or its motion impeded, for example, by engagement with the flexible chamber or between the flexible chamber and the interior, particularly the bottom, of the container. If the object should become so engaged and rendered immobile, or its free movement impeded, then mixing of the product prior to dispensing may be impaired.
Such impaired mixing can occur, for example, in a pressurized container which includes a flexible, expandable propelling chamber of the type disclosed in U.S. Pat. No. 3,718,236 issued on Feb. 27, 1973 entitled PRESSURIZED CONTAINER WITH NON-RIGID FOLLOWER. In a container of the type disclosed in the '236 patent, reactions in a pouch or bag-like enclosure generate gas which expands the pouch and exerts pressure on the product to dispense it from the container through an outlet valve upon actuation thereof. A glass or steel ball disposed in the product for mixing the product upon shaking the container could become engaged by the expanding pouch, particularly between the pouch and the container bottom when the pouch has expanded and occupies almost all of the volume in the container.